It depends on the planet . Other planets within our solar system are certainly within our technological reach. Planets orbiting other stars are more problematic. If the idea of 'generational ships' came to fruition, there would be no need for FTL travel, so those planets are also 'within reach'.

If we put all our planetary resources and technical skill into the endeavor, I am willing to bet we could build a generational starship that could span the gulf to the next nearest solar system.

Whether anything would be there is another question. Aslo, since the best speed of the ship would, at best, be a couple percent of light speed our descendants might not want to disembark from the only home they ever knew for some dirtball of a planet.

But putting humans on another planet in another system is doable with close to our present technology (we'd need a crash Apollo program again).

If we could get the Big Fat Ship (BFS) up to 1% of the speed of light we could make the transit to the nearest star in 4 or 5 generations.

Pesse (Of course, it might be nice to know if anything is there first...) Mist

If by "we" is meant the United States, then it cannot be stated often enough that the entire impetus for the US entrance into the "space age" was entirely political, an artifact of the Cold War. Once the "space race," with the Soviet Union," was "won" by a number of moon landings (and by a Soviet abdication of manned space attempts beyond earth orbit), the US saw its manned space program coopted by a Shuttle program that was driven by military needs. Science was appended to this, but the foundation was military.

This is not a denunciation; it is a simple statement of the fact.

Today, with complex military problems that are largely involved with less technological opponents, not technological equals, the impetus for state-financed manned space exploration beyond earth orbit is non-existent (I am aware of private ambitions in this regard but doubt that the necessary resources are really there). It is possible that a successful manned landing someplace by a rival nation (no need to name names) could tweak US nationalist pride into making a commitment to spending the money required for future US manned space exploration, but it would happen under very different economic conditions than those the US enjoyed in the 1950s-1970s and would be very difficult, in part because the nature of US "civilization," too, is changing rapidly from the one that entered the space age over half a century ago.

I don't disagree with any of what you wrote, Joad, but the fact that we agree *is* in large part the problem itself. The overwhelmingly political nature of space projects is not limited to the U.S. Virtually every nation that has developed a space program has done so, at least initially, for political reasons. The irony is that the technological and economic benefits of space far outweigh the value of bragging rights, yet "we" (and this is an inclusive we, not merely a jingoistic one) all too often fail to acknowledge this, and end up with the equivalent of eating the seed corn, or allowing it to all be transferred to Monsanto.

Perhaps the cold war mentality has ossified our attitudes towards space, or perhaps it's too abstract for the average person to grasp, and thus support. I don't know. But we're doing ourselves (in a global sense) a huge disservice by neglecting the opportunity for advancement that space offers.

While I agree that for now corporations like SpaceX, Bigelow, Sierra Nevada, Orbital Sciences, and even Boeing lack the resources to do any more than take small bites out of the pie, and most of these may not have the ambition to even try, my hope remains that somebody will make enough money in that business to inspire others to join.

I'm not happy that the only way "we" are likely to get excited about space again is if it becomes immediately profitable to a small cadre of organizations, and I DON'T like the approach that Jeff Bezos is taking of patenting every space flight-related item he can draw a picture of (Particularly since amid all that flurry of patenting he's still not launching anything). But if that's what it takes to get us off the planet and pushing deeper, then better that way than no way.

Hopefully, when the corporations start to succeed, the governments will come around, and maybe we'll see not only international cooperation for important explorations, but even significant budgetary commitment.

"Is" and "ought" are different things, as you know, Dave. While I certainly have my own list of "oughts," I have also concluded that discussing "oughts" in a public forum is useless—especially before there is an agreement on what "is," and in today's globally polarized environment, agreement on even what "is" is impossible.

I think both of you have done a good job of identifying some of the primary difficulties modern society faces with respect to the challenge of space travel.

There is, I believe, a potentially stronger motivation to re-engage in our attempts to escape the gravity well. I know you've heard me say this before, but the most basic tenet of ecology is that organisms alter their environment. This is neither good nor bad, it's 'nature'. We humans are incredibly capable when it comes to garnering ever more resources to support our exponentially increasing population. So, I postulate that the need for resources is highly likely to motivate exploration.

To return to the topic, I believe it is also much more likely that long, long before we go traipsing off to an unknown, dirt ball planet, we'll return to local space in search of those resources. Add a few generations to that scenario and I suspect we'll have done a pretty good job of filling our immediate neighborhood.

"Is" and "ought" are different things, as you know, Dave. While I certainly have my own list of "oughts," I have also concluded that discussing "oughts" in a public forum is useless—especially before there is an agreement on what "is," and in today's globally polarized environment, agreement on even what "is" is impossible.

Well that depends on what your definition of "is", is. (I've been waiting forever to use that one on my own behalf! )

There is the "hard - is", unchanging facts of nature, such as "The speed of light in a vacuum *is* 299,792,458 m/s", or "The mass of an electron *is* 9.10938291 × 10-31 kilograms". There is the "firm - is", facts of nature that are true as of the present time, but are likely to change as things evolve, such as "The length of a sidereal day *is* 0.99726958 that of a mean solar day", or "The airspeed velocity of an unladen swallow (European, not African) *is* roughly 11 meters per second."
There is the "Civic/Historical - is", facts of history or civilization or geography that are well established, but may change if circumstances do, such as "The capital city of Texas *is* Austin", "The southernmost point of any state of the U.S. *is* the south coast of Hawaii".

THEN there is the "Soft - is", things that are true only because there is a local or temporal consensus, and can change fairly easily. This kind of *is* is, in fact, manufactured by the cultural acceptance of "oughts". A good example of this is "There *is* a lack of national or global commitment to an intensive program of space exploration".

BTW, I made up all these categories out of thin air, which *is* probably obvious to most of you. That categorization is another example of a "Soft - is", unless there's a consensus that it's wrong.

I think there's a broad agreement here that the *is* in question is that there *is* no real appetite among the general population for major national commitments to space travel. If there was, we would be doing it. So if true, according to your post above, we've already won half the battle.

That's where the "ought" comes in. Yes, most of the time there's no point in discussing "oughts" on a public forum, although if you take a sweeping survey of internet fora all over the world, I suspect you'll find that the great majority of all discussions involve exchanges of "oughts". Whether anyone's personal "oughts" ever change as a result of these discussions is debatable, but they're certainly popular. Anecdotally, I've found that a few of mine have been modified over time, and I've known a few other individuals who's opinions have changed due to informed and deep internet discussions combined with real curiosity and subsequent research.

Anyway, no amount of advocacy can change the hard or firm *is*-es. They are fixed by forces beyond our control, for the most part. However, the "Soft - is" is ripe for advocacy. And advocacy, properly managed, the skillful transfer and promotion of "oughts", has been proven time and time again to change these kinds of established facts, sometimes for better, sometimes for worse. The Civil Rights movement is a perfect example of "ought-advocacy" that changed the current *is*.

Now this issue isn't anything like Civil Rights, particularly due to the fact that there are good and rational valid arguments not mired in prejudice on both sides. In a way, that also makes the discussion more interesting, and more educational for all concerned.

So yes, I have my "oughts", and a desire to change what *is*. And I think it's possible. You may with very good reason disagree with my "ought", holding that the current *is* is perfectly satisfactory. Other than by arm wrestling, this kind of issue will be resolved eventually in one way or the other, either by natural evolution of civilization, environment and technology, by catastrophe, or by a change in the public mood. I'm personally hoping to take advantage of the first, avoid the second, and be annoying about the third.

There is, I believe, a potentially stronger motivation to re-engage in our attempts to escape the gravity well. I know you've heard me say this before, but the most basic tenet of ecology is that organisms alter their environment. This is neither good nor bad, it's 'nature'. We humans are incredibly capable when it comes to garnering ever more resources to support our exponentially increasing population. So, I postulate that the need for resources is highly likely to motivate exploration.

Forgive my cynicism, but mankind is far more likely to 'prune back' its population than to expend limited resources heading off into space.

The Apollo program came out of a fear of the Soviets, not from any egalitarian notions. Exploration for the sake of exploration falls way down on the priority list. That's why we stopped sending men to the moon. No threat-no reason to go.

When technology allows relatively cheap escape from our gravity well, that will spur further reaching out. But right now, there is no overwhelming driving force or fear that will cause major resources to be committed to, say, a manned Mars mission.

I love space but I see no reason to make the huge commitment to send men to Mars right now. I mean I love large TV's, but also don't allocate the thousands for a 75" Plasma screen!

Another problem we have is legacy: Everyone wants their own. To support projects that may span a couple generations is very difficult. That's why a president may expand some grandiose mission only to see the next president trash it for his own vision.

There is, I believe, a potentially stronger motivation to re-engage in our attempts to escape the gravity well.

And this is the part where most folks are a little bit misled by popular conception. Everybody seems to think the earths gravity well is a huge detriment to 'going to the stars'. Reality is, earths gravity well is a difficult enough problem for current propulsion systems, but, it pales in scale compared to the REAL gravity well we have to escape.

The gravity well of our sun is many orders of magnitude larger, and a much more difficult problem, but, we dont really consider it today, because we still haven't got out of the smaller one with any sort of efficient mechanism.

A direct trajectory out of the solar system, that doesn't rely on multi year hallman trajectories and gravity assist encounters with other objects, is beyond the technology we have today.

As Ion propulsion is created for these asteroid chaser drones the most likely candidate would be mars..

Just getting to Mars faster is only half the battle. Once there, it's necessary to decelerate. The faster the approach, the longer the slow-down. Some of the Mars landers have had to make multiple elliptical orbits, barely skimming Mars' thin atmosphere on each pass, in order to slow down enough to initiate the landing sequence. The process often takes months. It's not an insurmountable problem (other issues relating to human health and safety are far more vexing), but it does prove, once again, that there's no such thing as a free lunch.

Why do we need to send humans to other planets? Why not send robotic missions (also sample return missions)? I am not sure what astronauts will accomplish which robotic landers cannot? The desire to have a human foot-print on the surface of another planet though exciting is not really worth the cost, risk and what could be achieved by undertaking such a mission.

Why do we need to send humans to other planets? Why not send robotic missions (also sample return missions)? I am not sure what astronauts will accomplish which robotic landers cannot? The desire to have a human foot-print on the surface of another planet though exciting is not really worth the cost, risk and what could be achieved by undertaking such a mission.

What will make it worth the cost is the potential for profit. The one thing humans can possibly do on other planets that robots cannot is live, inhabit, colonize, and reproduce there.